In our analysis, the significance of the detection at sodium D\(_{1}\)  is less than for D\(_{2}\) . This is consistent with the results of [1]}, who do not detect an absorption at Na D\(_{1}\) .
In general, the absorption cross-section
of the D\(_{2}\)  line is up to two times larger than in D\(_{1}\)  [2]}, [3]}.
